The purpose of this core is to support the field activities. Our group also has a full time field station with telephone and accommodations for over 10 people. A small laboratory is also present in the field station. The field study sites are located within a half an hour of the field station over asphalt road. We also have access to peasant markets for buying T. solium infected pigs. These are to be used for Component 2 and 3 studies. We will use palm top computers that have been programmed with special screens for the entry programs. These programs will have consistency and numerical checks built in to reduce digitation errors. Each day the entries will be downloaded into a central data file as well as having a printout made so that a paper trial exists. This should enable us to have immediate one lie data analysis. Each weeks data sheets will be sent back to each of the units. This unit will use GPS equipment to collect data on spatial- related variables. This information will be organized with laboratory and field information in a GIS data base.